Inflation is subject to recurring pattern over the course of year and so the CPI. Consumer behavior exhibit seasonal features; in many industrialized countries consumer spending goes up to Christmas, which often followed by price discounting in January; then demand for energy and warm cloths is higher in the cold winter months than in the summer and so on. To the extent that such behavior causes prices to fluctuate this should in turn be reflected by seasonal movements in the consumer price indices. Government behavior can also influence these cycles

Existence of Seasonality complicates the analysis of inflation-linked bond prices. There are significant advantage in a well-established index being employed, but such indices often exhibits seasonal pattern. Potential solution for this is to use a seasonally adjusted price index, but in general such series is less understood. Choice of a seasonal price index leads to two issues; expected nominal size of future cash flows will be impacted by their timing with respect to the seasonal pattern, and yields quoted using standard market convention will also be impacted.